1. Field of the Invention
This invention is concerned with a detection apparatus for weaving defects of a carpet or rug.
2. Description of the Prior Art
Many types of apparatuses to detect weaving defects of a carpet or rug have been proposed and actually been applied. However, they have many disadvantages such as that the detection sensor contacts with or is very close to the ground fabric and moves in the direction of the width of the ground fabric, causing the sensor to catch the weaving defect at the projected portion of the detection sensor. This has prevented the smooth moving of the detection sensor, or has enlarged the defect by the catching of it.
Further, the conventional detection apparatuses employ only one detection sensor to detect a weaving defect generated on the ground fabric, thereby detecting negligibly small weaving defects or yarn scrap, each time stopping the weaving machine and causing a reduction of working efficiency.
Further, the above stated conventional detection apparatuses have been very complicated to use because the detector, which moves on the surface of the ground fabric in the direction of its width to detect a weaving defect generated on the ground fabric, is fixed so as to make its bottom surface to be parallel with the surface of the ground fabric. Therefore, the sole of the detecting sensor is not parallel with the face of the ground fabric in cases where, for example, the spiked roller of the weaving machine is elevated and the ground fabric is moving upwardly inclined, or the case where inclination of ground fabric changes in accordance with weaving methods. Therefore it was necessary to use a different detecting sensor each time which was designed to make the sole lie parallel to the ground fabric in accordance with the installation of the ground fabric.
Also, because conventional detecting apparatuses were provided with no means to absorb vertical vibration of the detecting sensor, they had such disadvantages that vertical vibrations of the detection sensor could disturb the movement of the detecting sensor during its movement or cause failure in the electric system of the detecting sensor, or the detection accuracy could vary by the change of the distance between the bottom of the detecting sensor and ground fabric.